Fig. 5.

(a) The inter fragment interaction energies (IFIEs) between compound 12 and each Mpro residue for the structure of cluster 2. The total IFIE between compound 12 and all Mpro residues is also shown. The red bars indicate the residues with attractive IFIE, the size of which is larger than 10 kcal/mol. (b) The interacting structures between compound 12 (ball-and-stick model) and selected important Mpro residues (stick model) in the optimized structure of the Mpro + compound 12 complex for cluster 2. Hydrogen bonding, electrostatic, and NH-π interactions are indicated by red, blue, and orange lines, respectively. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)